Test difference between NHS and Blue Horizon Medical

[kaz90]

Could anyone help me please, I have been regularly using blue horizon thyroid tests to monitor my thyroid activity as I believe I have hypothyroidism.My Tsh level has been creeping up all year, the latest test results show this.

TSH 4.36 High (0.27-4.20) mlU/L

T4 Total 84.6 (64.5-142.0)mol/L

Free T4 11.27 Low (12-22)pmol/L

Free T3 4.76 (3.1-6.8)pmol/L

The doctors comments 'if you are not taking thyroxine already, this result is likely to represent a new diagnosis of hypothyroidism (underactive thyroid gland). '

However NHS test for TSH done the result was this TSH 2.0mu/L (0.35-5.5). my results always come in the 2 range. So confused.... why are the tests so different ?

Can anyone offer advise?

Thanks

Kaz90

[greygoose]

Are they both done early in the morning, and fasting?

[kaz90 in reply to greygoose]

nhs test was done around 10.30am , I do the blue horizon around 7.30am neither are fasting.

[greygoose in reply to kaz90]

OK, so that explains the difference. Your TSH will obviously be higher at 7.30 than at 10.30. But, TSH also drops after eating, so if you did an early morning fasting test next time, your TSH will be higher.

[kaz90 in reply to greygoose]

Thank you so much for that advice.

[greygoose in reply to kaz90]

You're welcome.